Problem Statement

We have $N$ integers $A_1, A_2, ..., A_N$.

There are $\frac{N(N-1)}{2}$ ways to choose two of them and form a pair. If we compute the product of each of those pairs and sort the results in ascending order, what will be the $K$-th number in that list?

Constraints

• All values in input are integers.
• $2 \leq N \leq 2 \times 10^5$
• $1 \leq K \leq \frac{N(N-1)}{2}$
• $-10^9 \leq A_i \leq 10^9\ (1 \leq i \leq N)$

Input

Input is given from Standard Input in the following format:

N K
A_1 A_2 \dots A_N

Output

Print the answer.